While using SSDs instead of HDDs has an appeal, for the media storage type of project I have, two main thoughts :-
- Firsty, unless you're concurrently serving quite a few people with video, you don't need the speed they offer and HDDs can cope perfectly well, and
- Cost. Media, and especially video, files can be pretty big. Admittedly, I've got quite a lot to get on to the system, but even a single film at DVD quality and in a compressed format, can take several GB. My newest NAS (and yes, you could easily build your own, but I'll use the terms interchangeably) has four 18TB drives in it, with space for two more in that box. If you get to the point of needing that degree of space, doing it with even relatively slow SSDs is prohibitively expensive.
The 18TB drives were some £270 each. I suspect you'd pay more than that for a 4TB SSD. The issue for me there was cost/TB.
As an aside, I didn't mention it but that 6-bay NAS has a couple of M.2 NVMe bays in it and I'll be flling those with SSDs, but just not with a view to the media server side of it. The NAS has other used too.
Haven't heard from you for a while. Hope things are going well.